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02-08-2011, 07:32 AM #1
How does one locate and install a front sight ramp?
I'm rebarreling a custom sporterized Springfield '03 that my father-in-law had built for my wife when she was in high school (1956 - 1960). It was test fired with military ammo that had corrosive primers in it, not cleaned, and the barrel was destroyed. I tried to shoot it, bullets went sideways through the paper at 50 yards. She brought it with her, along with 6 other rifles and a revolver, when we were married almost 43 years ago.
I decided to rebarrel it for her as a 43rd anniversary present. I'm almost there.
I recently posted pictures of cutting the extractor groove in the barrel breech for an '03 Springfield action, that was for this project. Today I got the stock modified so that tne new barrel fits. This is what it looks like so far:
The barrel needs a front sight ramp, front sight, final polish and bluing.
I did some measuring on the old front sight as installed on the old barrel. From the centerline of the old barrel to the top of the front sight bead is 1.022". The ramp height measured from the top of the barrel to the bottom of the dovetail is 0.380". The barrel OD at the front sight is 0.594". The front sight itself from bottom of dovetail to top of sight is 0.345"
The new barrel OD at the front sight location is 0.667". To get the same height, bore centerline to top of bead, I'd need a ramp with a height of 0.345". Brownell's sells one, Williams, that mounts iwth a scre that's 0.3445" top of barrel to bottom of dovetail. That will work if this is in fact the right way to determine the required height.
Is the above a reasonable way to figure out front sight ramp height, top of barrel to bottom of dovetail?
If not, how do I go about figuring out what height front sight ramp I need?
Once the ramp is here, what is the best way to decide where it should be on the barrel so the rear peep sight zeros about centered?
This, like some other features of this project (square threads and cutting an extractor groove), is a first for me. Any suggestions are welcome.
02-08-2011, 08:52 AM #2
The Brownells catalog has a chart/explanation for establishing front sight height in it. For top center, I might just eyeball it or set the action up on a surface plate that is level and make it top dead center with squares or a level. There is a leveling tool made that is designed just for this application and I imagine Brownells sells it.
02-08-2011, 11:33 AM #3
02-09-2011, 04:31 PM #4
Hi Fitch. That's a williams peep sight, correct?
When I fitted one of those to my daughter's 22, I did the front sight height by
guess-n-by-gosh by having the rifle sighted in using the blade sight, and the
the stock front sight.
Then I simply measured the altitude of the front sight from the barrel centerline
(using the diameter at the front sight) and the altitude of the more-or-less correct
rear sight notch, again at the barrel diameter near the sight to get altitude above
With those calculated numbers in hand, I installed the new peep sight and more
or less put all the adjustments at mid-range.
Then measured the peep sight center above barrel center dimension.
That, subtracted from the original sight dimension above centerline, gave
me the number to *add* to the original front sight.
Brownell's had one that tall - *just*. It took a few hours of page-turning
to get the style I (she!) wanted in the height needed.
This exercise was one reason I went with a marbles peep sight when I did my
22 - I could be adjusted to be as low as the original blade sight, and I could
retain the original front sight.
Best to you and yours - Jim
(nice gun btw. Also I'd say the wife's a keeper if she arrives with her own
02-10-2011, 05:45 AM #5
02-11-2011, 06:42 PM #6
By "locate" it means you are trying to determine what front sight height you need correct? And not how to find the centerline of the barrel to mount the front sight if I understand you correctly.
The fastest and simplest way IMHO is to remove the bolt and use either a cleaning rod or other metal rod and pass it through the barrel so it sticks out the breech and muzzle. Use a dial caliper (or depth micrometer but that is overkill) to measure the height from the top of the rod to the center of the rear sight aperture with the sight at its lowest elevation. Now measure the height of the top of muzzle end of the barrel to the rod and subtract it from the first measurement and there you go. It will take you less time to do than it did for me to type this.
02-11-2011, 06:44 PM #7
02-13-2011, 02:35 AM #8
02-13-2011, 06:43 AM #9
LOL. This is one reason I taught my daughter to shoot....
As for soldering, I'm not even close to a gunsmith so don't listen to me.
But I'd use 95/5 tin/silver soft solder if a low-temperature job was desired.
Stronger than regular lead/tin by about 3X.
02-13-2011, 07:44 PM #10
02-14-2011, 09:14 AM #11
Turns out the rear sight and the old ramp on the new barel are within 0.005" of the same height as close as I can determine.
There is bunch of adjustment in the rear sight, it could go an eighth of an inch lower than it is, and up a half inch or more. I just need to zero it at 100 yards and I'm good, so this is going to work. But at least I know that now.